The present disclosure relates to a semiconductor device, a base, and a method for manufacturing the semiconductor device and the base.
The use of light emitting devices using semiconductor light emitting elements such as LED's has expanded, and there is an increasing demand for improved emission efficiency. Such a light emitting device is generally configured such that a semiconductor light emitting element is housed in a resin case supporting lead frames and is sealed with a resin. Each of the lead frames has an upper surface on which a silver film serving as a reflective film is formed for the purposes of efficient reflection. Silver has a high reflectance. However, reflection of light involves absorption of light by a few percent. Furthermore, multiple reflections occur in the resin case, resulting in an increase in the amount of light absorption.
As an example of a method for improving emission efficiency, Japanese Patent Publication No. 2008-186946 discloses a light emitting semiconductor device comprising an enclosure having a recess and a light reflecting member disposed in the recess, wherein the light reflecting member is a stacked sheet constituted by a resin film and a plurality of dielectric films having different refractive indices and stacked on one surface of the resin film.
Japanese Patent Publication No. 2011-233555 discloses a light emitting element supporting member provided with a light shielding layer constituted by a base member and a reflector disposed on the base member, wherein the reflector is composed of a metal and one or more dielectric layers stacked on the metal.